# import numpy as np
# arr1 = np.array([1,2,3])
# print('一堆数组arr1:\n',arr1)
# arr2 = np.array((4.5,5.6,6.8),dtype='int32')
# print('一堆数组arr2:\n',arr2)
# arr3 = np.array([[1,2,3],[4,5,6]],dtype='float32')
# print('2x3的二维数组arr3:\n',arr3)


import numpy as np
arr1 = np.array([1.1,2.2,3.3])
print('一堆数组arr1:\n',arr1)
arr2 = np.array((-1,-2,-3),dtype='int32')
print('一堆数组arr2:\n',arr2)
arr3 = np.array([3,-2,2.3],dtype='float32')
print('2x3的二维数组arr3:\n',arr3)